fix(ssr): avoid transforming json file in ssrTransform

packages/vite/src/node/ssr/ssrTransform.ts

@@ -26,6 +26,31 @@ export const ssrExportAllKey = `__vite_ssr_exportAll__`
 export const ssrImportMetaKey = `__vite_ssr_import_meta__`
 
 export async function ssrTransform(
+  code: string,
+  inMap: SourceMap | null,
+  url?: string
+): Promise<TransformResult | null> {
+  if (url && url.endsWith('.json')) {
+    return ssrTransformJSON(code, inMap)
+  }
+  return ssrTransformScript(code, inMap, url!)
+}
+
+// json don't need to parse code it must be `ExportDefaultDeclaration`
+// so replace the "export default" to ssr "export default"
+async function ssrTransformJSON(
+  code: string,
+  inMap: SourceMap | null
+): Promise<TransformResult> {
+  return {
+    code: code.replace('export default', `${ssrModuleExportsKey}.default =`),
+    map: inMap,
+    deps: [],
+    dynamicDeps: []
+  }
+}
+
+async function ssrTransformScript(
   code: string,
   inMap: SourceMap | null,
   url: string